Method of molding

ABSTRACT

Disclosed is a method of molding molded articles, amongst other things.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/555,913 filed Nov. 2, 2006, the entire disclosure of which isincorporated herein by reference thereto.

TECHNICAL FIELD

The present invention generally relates to, but is not limited to,molding systems, and more specifically the present invention relates to,but is not limited to, a molding structure, and a method of molding,amongst other things.

BACKGROUND

Injection molding systems that are configured to produce molded articleshaving multiple layers of varying thermoplastic compositions typicallyhave a high capital cost relative to injection molding systems that areconfigured to produce molded articles of a homogenous thermoplasticcomposition. A molded article having multiple layers may be, forexample, a multi-layer preform, of the type that is blow molded into abottle. A typical multi-layer preform includes three layers, the innerand outer layer are made from a first thermoplastic composition, resin‘A’, such as polyethylene terephthalate (PET), while an intermediatelayer may be made from a second thermoplastic composition, resin ‘B’,such as ethylene vinyl alcohol copolymer resin (EVOH). The intermediatelayer of ‘B’ resin is commonly referred to as a barrier, as it functionsto prevent oxygen and other gases from permeating through the moldedarticle which may otherwise adversely affect the quality of a product,such as a beverage, that is sealed in the bottle.

The high capital cost of multi-layer injection molding systems presentsa capital burden for preform producers (converters), for example, whenpurchasing a multi-layer molding system without first securing firmcontracts to supply the multi-layer preforms. Today, the long lead timerequired to procure a multi-material molding system make it difficultfor converters to react quickly to business multi-layer preform supplyopportunities from the relatively fast-paced preform consumer marketwithout otherwise having idle multi-layer molding equipment at theready. A field upgrade of a purpose built mono-layer molding system isnot practical owing to the extent to which the molding structure of thesystem would need to be altered, not the least of which is a requiredmachining of the stationary platen to incorporate a passageway toaccommodate a second injection unit. The net effect of the foregoing isthat preform converters have been reticent to go after multi-layerpreform business.

U.S. Pat. No. 6,517,337 (Inventor: HEHL, Karl, Published: 11th February,2003) describes an injection molding machine having a plurality ofmodular drive groups that provides possibilities for the customer tooptimize the injection molding machine depending on the injection moldedproduct.

SUMMARY

According to a first aspect of the present invention, there is provideda method for molding a molded article. The method includes the steps offactory configuring a modular molding system having an initial-buildconfiguration for producing a molded article of a first moldingcomposition, and factory configuring the modular molding system to befield upgradable with a module to an upgraded configuration forproducing the molded article including a combination of the firstmolding composition and a second molding composition.

A technical effect, amongst others, of the aspects of the presentinvention is that the modular molding system provides the molder, suchas a preform converter, the ability to promote production capacity formulti-layer molded articles, for example, on a shorter notice and with alower initial capital equipment cost than heretofore possible. Uponsecuring a contract for the multi-layer preforms the molder need onlypurchase and field install the required module to upgrade thefunctionality of the molding system.

Preferable embodiments of the present invention are subject of thedependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the exemplary embodiments of the presentinvention (including alternatives and/or variations thereof) may beobtained with reference to the detailed description of the exemplaryembodiments along with the following drawings, in which:

FIG. 1 is a perspective view of a upgradable injection molding systemaccording to a first exemplary embodiment (which is the preferredembodiment);

FIG. 2 is another perspective view of the upgradable injection moldingsystem of FIG. 1.

The drawings are not necessarily to scale and may be illustrated havingphantom lines, diagrammatic representations and fragmentary views. Incertain instances, details that are not necessary for an understandingof the exemplary embodiments or that render other details difficult toperceive may have been omitted.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

With reference to FIG. 1, molding structure is shown that has beenconfigured for molding multi-layer molded articles, such as multi-layerpreforms. The molding structure includes a modular molding system 10having an injection unit 12 and a clamp unit 14. More particularly, themodular molding system 10 includes an initial-build configurationconsistent with a purpose-built mono-layer system with an upgrade moduleincluding the molding structure of a purpose-built multi-layer moldingsystem.

Alternatively, the molded article could be a simple multi-materialmolded article not having discreet layers.

The initial-build of the injection unit 12 includes an ‘A’ injectionunit. The ‘A’ injection unit 30 is arranged on a base 20. Moreparticularly, the base 20 includes a pair of rails 22 upon which acarriage 31 of the ‘A’ injection unit 30 is slidably arranged. Thecarriage 31 is connected to a stationary platen 100 of the clamp unit 14by at least one carriage actuator 24.

The ‘A’ injection unit 30 includes an extruder 32. Preferably, but notexclusively, the ‘A’ injection unit 30 also preferably includes ashooting pot 36. As shown, the shooting pot 36 is connected to theextruder 32 by a distributor 34. Each of the extruder 32, thedistributor 34 and the shooting pot 36 are connected to the carriage 31.Also shown is a screw drive 38 for operation of a screw (not shown),preferably by means of rotating and reciprocating of the screw in abarrel (not shown) of the ‘A’ extruder 32. The configuration and theoperation of the ‘A’ injection unit 30 is in keeping with knowntwo-stage injection units, the structure and the operation of which iswell-known to those skilled in the art, and need not be described in anydetail hereafter. The ‘A’ injection unit 30 is also shown as includingan ‘A’ hopper valve 39 for controllably connecting the extruder 32 witha supply of ‘A’ resin.

The injection unit 12 is configured, at initial-build, to receive a ‘B’injection unit 50. For example, the base 20 of the injection unit 12 isconfigured to include a pair of mounts 64 upon which a ‘B’ unit support60 is connectable. The ‘B’ unit support 60 comprises a base 61 and apair of rails 62.

The ‘B’ injection unit 50 is slideably arranged on the rails 62 of the‘B’ unit support 60. The ‘B’ injection unit 50 includes an extruder 52and a screw drive 58 for rotation and reciprocation of a screw (notshown) in a barrel (not shown) of the extruder 52. The drive 58preferably includes an electrical motor for screw rotation and ahydraulic actuator for screw reciprocation. Alternatively, the drive 58may be fully electric, fully hydraulic, or any combination thereof. The‘B’ injection unit 50 further includes at least one carriage actuator 52connecting the carriage 56 to the platen 100 of the clamp unit 14. Thenozzle 54 is preferably configured to cooperate with a nozzle shut-offactuator 108 for controllably connecting the mold (not shown) with theextruder 52. As will be described hereinafter, the nozzle shut-offactuator 108 is connected to the stationary platen 100. The ‘B’injection unit 50 further includes a nozzle 54 for connection of theextruder 52 to a mold (not shown). The ‘B’ injection unit 50 is alsoshown as including a ‘B’ hopper valve 59 for controlling a flow ofmolding resin from a reservoir (not shown) to the extruder 52.

The base 20 of the injection unit 12 includes a hydraulic power pack(not shown) on the non-operator side of the injection unit. The powerpack is accessible behind power pack covers 26, the power pack cover 26shown in FIG. 1 being in an open position for accessing the power pack.A walkway 16 is shown on the non-operator side of the injection unit 12.Not shown is a removable power pack cover adjacent to the ladder of thewalkway 16. At the rear of the injection unit 12, just behind thewalkway 16, is a rack 17 for accommodating a plurality of hydraulicaccumulators. The rack 17 shown in FIG. 1 is configured foraccommodating five cylinder-type hydraulic accumulators. The hydraulicaccumulators, as is generally known, are connected to the power pack(not shown) and with a power manifold 80 shown at the rear of theinjection unit 12. The power manifold 80 is in turn controllablyconnected with the actuation devices of the molding system 10. Forexample, a set of hydraulic hoses 82 are shown connecting the powermanifold 80 with the ‘A’ carriage actuators 24 and the screw drive 38.Also shown are a second set of hydraulic hoses 84 connecting the powermanifold 80 with the ‘B’ screw drive 58 and the ‘B’ carriage actuators24. As shown, the ‘B’ unit hydraulic hoses 84 are routed along the base20 in a service tray 19.

Along the operator side of the injection unit 12 are the main controlmodules 70. The main control modules include a machine controller 74,shown in hidden lines behind the doors of the module 70 as well as acontrol device 76 also show in hidden lines within the module 70. Thecontroller 74 and the control device 76 are interconnected by means of adata bus 78. Likewise the actuators and feedback devices of the moldingsystem, such as hydraulic actuators, servo motors, position sensors,pressure sensors, and the like are interconnected to the control device76 by the data bus 78 or alternatively or in combination with dedicatedwiring. The main control module 70 further includes a control interface79 for interconnection of an auxiliary control module 72, shown as afree-standing unit. The auxiliary control module 72 may include controlhardware such as servo drives, injection control cards, and servoamplifiers for controlling of the drive 56. The auxiliary control module72 may also include a controller for the barrel heaters of the ‘B’ unitextruder 52. The auxiliary control module 72 may also include athird-party heat controller for a hot runner of the mold (not shown) oran interface for connection therewith. The auxiliary control module 72may also include a dual-voltage control outlet for peripheral devicessuch as mixers or blenders. A data bus 78, power cable 77, and devicecable 79 are shown linking the main control module 70 with the auxiliarycontrol module 72

Alternatively, the main control module 70 may otherwise house thecontrol devices of the auxiliary control module 72.

With reference to FIG. 2, the structure of the ‘B’ unit support 60 isshown in more detail as including angle brackets 66 supporting the base61 of the ‘B’ unit support 60. The brackets 66 connectable to the mounts64 that are preferably integrated with the machine base 20. Also shownin FIG. 2 is a purge guard 90 for the ‘A’ injection unit 30. The ‘A’injection unit guard 90 preferably includes an access door through whichthe operator can remove drool from the extruder 32. The door (not shown)is preferably re-located on the non-operator side of the machine forease of access. Not shown is a ‘B’ injection unit purge guard that wouldotherwise mount to a purge guard mount 109 provided on the rear of thestationary platen 100.

The clamp unit 14 includes a base 102 upon which is slideably arrangedthe stationary platen 100. Also shown is a moving platen 110 that isslideably arranged on the base 102. A series of tie bars 18 interconnectthe moving platen and a clamp (not shown). The stationary platen 100includes a platen ear 101 as a projection extending from the operatorside of the platen 100. Alternatively the platen ear 101, and hence the‘B’ injection unit 50, could be located on the non-operator side of theplaten 100. The platen ear 101 defining a ‘B’ passageway 106 whichextends between the front and back of the stationary platen 100 forpassage of the machine nozzle 54 of the ‘B’ injection unit 50. Likewise,as shown in FIG. 2, there is provided an ‘A’ passageway 104 for passageof a machine nozzle 35 of the ‘A’ injection unit 30 for connection withthe mold (not shown).

The front face of the stationary platen includes the mold mountingpattern 103. The mold mounting pattern may include standard mountingconfigurations such as Euromap and SPI and may further includeproprietary mounting patterns for such mold makers as KORTEC (atrademark of Kortec Incorporated, Massachusetts, USA) for theirmulti-layer preform molds.

As indicated previously, the stationary platen 100 may include a nozzleshut-off actuator 108 connected to the platen ear 101 that is configuredfor operation of the valve of the nozzle 54 of the ‘B’ injection unit50.

The modular molding system 10 described hereinbefore is preferablyfactory configured to have an initial-build configuration for producinga molded article of a first molding composition. The modular moldingsystem 10 configured to be field upgradable with a module to an upgradedconfiguration for producing the molded article including a combinationof the first molding composition and a second molding composition. Theinitial-build configuration of the modular molding system 10 preferablyincludes a molding structure of a purpose-built mono-layer moldingsystem, and a first subset of a molding structure of a purpose-builtmulti-layer molding system. The module having a remainder subset of themolding structure of the purpose-built multi-layer molding system.

A technical effect of the exemplary embodiment of the present inventionis that the molder can defer capital expenditure for a multi-layermolding system until a contract for the molded article is made knowingthat the upgrade of the preconfigured monolayer molding system tomulti-layer can be purchased, assembled, and tested at the customer'sfacility in a short amount of time.

Accordingly, what follows are examples of differentiating technicalfeatures between a purpose-built mono-layer molding system and apurpose-built multi-layer molding system.

For example, the injection unit walkway 16 is preferably moved from theoperator side to the non-operator side as shown, but that there is spaceon the operator side to accommodate the injection unit 50.

Alternatively, the accumulator rack 17 may include an extra mount for anadditional accumulator as required to increase the capacity of thehydraulic system for operation of the injection unit 50.

Alternatively, the ‘B’ unit hydraulic hoses 84 and electrical controlcables 85 for the ‘B’ injection unit may be pre-configured in servicetrays 19 on the injection unit base or at the very least, the servicetrays 19 are provided and the hydraulic hoses and electrical cables 84and 85 would be supplied at the time of upgrade.

Alternatively, the injection unit base 20 would be pre-configured toinclude the mount 64 for the ‘B’ unit support 60.

Alternatively, the power pack cover (not shown) that is arranged behindthe walkway 16 would need to be removable because the walkway 16 wouldprevent the power pack cover 26 from being opened.

Alternatively, the main control module would be configured to includethe control interface 79 for interconnection of the auxiliary controlmodule 72. The power manifold 80 would be pre-configured to includeconnections for supplying hydraulic fluid to the ‘B’ injection unit. Theport for the ‘B’ injection unit on the power manifold 80 would beplugged at the factory, the power pack 80 otherwise configuredpreferably for a continuous supply of high pressure oil to the ‘B’injection unit once connected.

The base 20 of the injection unit encompasses a hydraulic tank.Alternatively, the tank may need to have a capacity that's in excess ofa typical mono-layer to accommodate the ‘B’ injection unit 50.

Alternatively, the ‘A’ purge guard 90 would require that the door bemoved to a non-operator side because the door, which would normally beon the operator side, is obstructed by the inclusion of the ‘B’injection unit 50 and that also the ‘A’ purge guard preferably includesan operator side extension.

Alternatively, the stationary platen 100 would be provided with coversfor the ‘B’ passageway 106 preferably on the front end and backs of theplaten, although possibly only in the front of the platen.

Alternatively, the gates of the molding system which are not shown wouldneed to accommodate the platen ear 101.

Alternatively, other subtleties of the factory assembly of the modularmolding system (10) may include the orientation of the barrel heaters(not shown) of the ‘A’ injection unit 30 such that the clamps (notshown) of the heaters are accessible from the non-operator side for easeof system maintenance.

Alternatively, a computer-readable product is provided, the productembodying one or more instructions executable by the controller 74 forcontrolling the control device 76′ for the ‘B’ injection unit 50, andinterface screens on the human machine interface (not shown).

Alternatively, a spacer (not shown) is provided for a molded articlehandling device to align the molded article with the mold.

The first subset of the purpose-built multi-layer molding systemconfigured with the initial-build configuration from the factorypreferably includes the stationary platen 100 having the ‘A’ passageway104, the stationary platen 100 having the ‘B’ passageway 106, the mount64, the main control module 70 including the controller 74, the controldevice 76, and the control interface 79, the power manifold 80, and acover plate for the ‘B’ passageway 106.

The first subset may also include the expandable accumulator rack 17,the ‘A’ purge guard 90, the ‘B’ service tray 19, the walkway 16, and thegate.

The remainder subset of the purpose-built multi-layer molding systemconfigured with the module for field upgrading of the modular moldingsystem preferably includes the ‘B’ injection unit 50, the ‘B’ unitsupport 60, the control device 76′ for the ‘B’ injection unit.

The remainder subset may also include the auxiliary control module 72including the control device 76′ of the ‘B’ injection unit, theauxiliary control module 72 configured for connection with the maincontrol module 70 through a control interface 79.

The remainder subset may also include the computer-readable product.

Other molding structure that may accompany the module with the remaindersubset includes the ‘B’ nozzle shut-off actuator 108, the ‘B’ purgeguard, the ‘B’ hopper valve 59, the hydraulic hose 84, the cable 85, andthe spacer for the molded article handling device. Likewise, the modulemay include auxiliary equipment for the molding system such as a barrierdrier for the ‘B’ molding composition, and auxiliary equipment such as ashuttle table for use with the clamp unit 14.

An exemplary method of the present invention includes the steps offactory configuring a modular molding system 10 having an initial-buildconfiguration for producing a molded article of a first moldingcomposition, and factory configuring the modular molding system 10 to befield upgradable with a module to an upgraded configuration forproducing the molded article including a combination of the firstmolding composition and a second molding composition. The method alsopreferably includes the steps of factory configuring the initial-buildconfiguration of the modular molding system 10 to include a moldingstructure of a purpose-built mono-layer molding system, and the firstsubset of a molding structure of a purpose-built multi-layer moldingsystem. The method further including the step of field configuring themodular molding system 10 to include the module having the remaindersubset of the molding structure of the purpose-built multi-layer moldingsystem.

The description of the exemplary embodiments provides examples of thepresent invention, and these examples do not limit the scope of thepresent invention. It is understood that the scope of the presentinvention is limited by the claims. The concepts described above may beadapted for specific conditions and/or functions, and may be furtherextended to a variety of other applications that are within the scope ofthe present invention. Having thus described the exemplary embodiments,it will be apparent that modifications and enhancements are possiblewithout departing from the concepts as described. Therefore, what is tobe protected by way of letters patent are limited only by the scope ofthe following claims:

1. A method for molding a molded article, comprising the steps of:factory configuring a modular molding system having an initial-buildconfiguration for producing a molded article of a first moldingcomposition; factory configuring the modular molding system to be fieldupgradable with a module to an upgraded configuration for producing themolded article including a combination of the first molding compositionand a second molding composition.
 2. The method of molding of claim 1,wherein: the step of factory configuring the initial-build configurationof the modular molding system includes the steps of: factory configuringa molding structure of a purpose-built mono-layer molding system;factory configuring a first subset of a molding structure of apurpose-built multi-layer molding system.
 3. The method of molding ofclaim 2, further including the step of: field configuring the modularmolding system to include the module having a remainder subset of themolding structure of the purpose-built multi-layer molding system. 4.The method of molding of claim 2, wherein: the step of factoryconfiguring the molding structure with the purpose-built mono-layermolding system includes the steps of: factory configuring an injectionunit having an ‘A’ injection unit; and factory configuring a clamp unit.5. The method of molding of claim 12, wherein: the step of factoryconfiguring the molding structure of the purpose-built multi-layermolding system includes the step of configuring at least a subset of: a‘B’ injection unit; a stationary platen having an ‘A’ passageway foraccommodating a nozzle of the ‘A’ injection unit; a stationary platenhaving an ‘B’ passageway for accommodating a nozzle of a ‘B’ injectionunit; a mount connected to the injection unit, the mount connectablewith a ‘B’ injection unit support; a ‘B’ unit support for supporting a‘B’ injection unit; a main control module including a controller linkedwith a control device for the ‘A’ injection unit and a control devicefor the ‘B’ injection unit; a computer-readable product embodying one ormore instructions executable by a controller for controlling at leastone of: (i) a control device for the ‘A’ injection unit, (ii) a controldevice for the ‘B’ injection unit, and (iii) a human machine interface;a power manifold connected to the injection unit configured to beconnectable with a ‘B’ injection unit; an accumulator rack configured toreceive an additional hydraulic accumulator; a hydraulic tank having ahydraulic oil capacity that is at least sufficient to accommodate arequirement for a drive for operation of the ‘A’ injection unit and adrive for operation of a ‘B’ injection unit. a ‘B’ nozzle shut-offactuator; an ‘A’ purge guard with a non-operator door access; a ‘B’purge guard; a ‘B’ hopper valve; a ‘B’ service tray connected to theinjection unit, ‘B’ the service tray configured for routing at least oneof a hydraulic hose or a control cable to a ‘B’ injection unit; awalkway configured on the non-operator side of the injection unit; ahydraulic hose for linking a drive of a ‘B’ injection unit with a powermanifold of the injection unit; a cable for linking a drive of a ‘B’injection unit with at least one of a control bus and a power bus of theinjection unit; a spacer for a molded article handling device; a gatefor the clamp unit configured to enclose a platen ear of a stationaryplaten.
 6. The method of molding of claim 5, further including the stepof: configuring the main control module to include a control interface,the control interface configured for linking the control device of the‘B’ injection unit that are arranged in an auxiliary control module. 7.The method of molding of claim 5, wherein: the step of factoryconfiguring the molding structure of the purpose-built multi-layermolding system includes the step of configuring the molding structure ofthe purpose-built multi-layer molding system to further include anauxiliary injection unit for supplying a further molding composition: 8.The method of molding of claim 2, wherein: the molded article is amulti-layer preform.
 9. The method of molding of claim 3, wherein thestep of configuring the first subset includes the step of configuring:the stationary platen having the ‘A’ passageway; the stationary platenhaving the ‘B’ passageway; the mount; the main control module includingthe controller, the control device, and the control interface; the powermanifold; and a cover plate for the ‘B’ passageway.
 10. The method ofmolding of claim 9, wherein the step of configuring the first subsetfurther includes the step of configuring: the accumulator rack; the ‘A’purge guard; the ‘B’ service tray; the walkway; the gate.
 11. The methodof molding of claim 3, wherein the step of configuring the remaindersubset includes the step of configuring: the ‘B’ injection unit; the ‘B’unit support; the control device for the ‘B’ injection unit.
 12. Themethod of molding of claim 11, wherein the step of configuring theremainder subset further includes the step of configuring: an auxiliarycontrol module including the control device of the ‘B’ injection unit,the auxiliary control module configured for connection with the maincontrol module through a control interface.
 13. The method of molding ofclaim 11, wherein the step of configuring the remainder subset furtherincludes the step of configuring: the computer-readable product; the ‘B’nozzle shut-off actuator; the ‘B’ purge guard; the ‘B’ hopper valve; thehydraulic hose; the cable; the spacer.